All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
We could not confirm the authenticity of the story of ‘Umar burying his daughter alive, despite its widespread publicity, in any of the references of history, biography, and the other Islamic resources and books we have at hand. Moreover, we do not see any benefit in searching for the authenticity of this story. Even if the story is proved authentic, then it will have no negative effect on ‘Umar since embracing Islam expiates all the previous sins.
Allaah Knows best.